Septic systems and many other wastewater treatment systems depend upon a disposal field for final treatment and disposal of the effluent wastewater. The most common types of disposal fields are shallow trenches filled with a porous medium. There are a variety of disposal fields; each is designed to address various site conditions and restrictions. These conditions include organic loading of the wastewater, soil permeability, the depth of impervious substratum, the depth of soils over openly fractured bedrock, the grade of slopes, the amount of land available, the sensitivity of groundwater in the area, and the depth of the water table.
Known disposal fields include mound systems, peat systems, and sand filters, for example. Dispersal and final treatment occurs as the effluent flows over and through the porous medium, as it infiltrates into the soil, and as it percolates through the soil. The treatment is a result of a combination of physical, biologic, and chemical transformations. Current technologies generally dispose of wastewater that has been treated through an aerobic process or other technologies by employing a drip irrigation system, utilizing an above ground sprinkler system, direct discharge to lakes or streams, or through a buried disposal field.
The success of a disposal field is determined by a variety of factors that include the hydraulic loading rate, the site characteristics discussed above, the organic loading of the effluent wastewater, and design criteria. All of these factors are considered in determining the length and size of the disposal field. The result is generally a large disposal field, usually on the order of 150 feet by 200 feet, that is expensive and unsightly or not feasible due to size or other site constraints.
This invention provides a compact, efficient, visually appealing, and economical means for dispersal of treated effluent wastewater from processes such as aerobic treatment systems. It is especially useful where a minimum vertical separation is required between the discharge point and the water table, or where limited land surface space is available. The source of the wastewater can be from residential, commercial, or industrial applications, for example. The treatment process is not limited to aerobic treatment systems, but the effluent should be sufficiently treated by the system prior to dispersal by the system of the present invention.
Because the water is pretreated, biomass growth is limited since the effluent wastewater has most of the organic loading removed. Also, suspended solids have been reduced to very low levels. This reduces the amount of plugging in the interstitial space of the soil particles. As a result, material for the dispersal field can be selected based on its hydraulic loading characteristics with very little consideration required for the organic loading of the wastewater or the retention time necessary to achieve effluent treatment.
The present invention is a compact water dispersal system located on an outdoor ground site. The system includes a water treatment system resulting in treated water with an organic loading of less than about 20 ppm and a suspended solids concentration of less than about 20 ppm. The water flows from the water treatment system to an interior dispersal pipe having a plurality of perforations. Through the perforations, it flows into an exterior dispersal pipe surrounding the interior dispersal pipe, the exterior dispersal pipe also having a plurality of perforations. The exterior dispersal pipe is surrounded by a layer of wicking material. A volume of fill material surrounds the interior dispersal pipe, the exterior dispersal pipe, and the layer of wicking material, thereby dispersing the water therefrom.